Better adaptation between tokens and token holders

摘要

The token is in the form of a circular disc that is inserted in a holder attached to the trolley. The token (1) and the holder (6,7) are of the same thickness, with the edge of the token rebated (4) to fit in a slot (10) in the end of the holder. The end of the holder is shaped to form a smooth surface when the token is introduced. The tongue at the end of the token has a transverse ridge (5) on top and bottom surfaces. The slot has recesses (11) on its inner surfaces to accept the ridges on the tongue of the token, holding the token in place when it is inserted in the slot.